US1893984A - Alloy - Google Patents

Description

Patented Jan. 10, 1933 lie mew lug.

This invention relates to an alloy which contains copper as its principal constituent and minor amounts of nickel and beryll um. A principal object of the invention is to obtain a material having properties which permit of its use for any purpose for which copper is used at the present time and which in addition may have imparted to it by suitable heat treatment hardness and strength far in excessot that possessed by metallic copper.

lln my Patent 1,658,180, dated February 7, 1928, l have disclosed that copper and copper alloys containing regulated minor amounts of one or more of certain silicides, among them nickel silicide, Ni Si, will assume a remarkably hard and strong condition if subjected to certain heat treatment of the kind to which the term age-hardening is usually applied in the art. I have now discovered that a copper alloy containing, in place of nickel silicide, minor amounts of nickel and beryllium may be worked and heat treated in a more or less similar manner.

'10 min. ball) of 52. The quenched a For example, an allow containing 95.7% copper, el% nickel and .3% beryllium can be hot or cold rolled, or otherwise worked, and after the rolling operation subjected to a softening treatment comprising quenching from above 900 G. In this state the alloy is very soft andductile, and shows a tensile strength of 48,000 pounds per square inch with elongation in two inches. It also possesses a Brinell hardness (500 kg. load,

oy can be hardened by subjecting it to a second heat treatment which comprises heating at a temperature within the range of about 350 C. to 700 C. and holding it for a time, depending upon the temperature used and the hardness desired. Heating fora period or approximately l8 hours will secure maximum hardness when a temperature oi? 350 C. is used, while at a temperature-oi 7 00 0. heating for 2 hours will sufice. Alloys of the composition above-mentioned have, when subjected to a hardening heat treatment, at-

tained a Brinell hardness of and a tensile strength of 90,000 pounds per, square inch with 15% elongation in two inches. The allnpplicatlon filed tlctober 20, 1090. Ito. 148,017.

.lhe alloy in the unquenched state is further characterized by the property of self-hard ening if air cooled or furnace cooled from 900 G; H cooled in a slow way as compared with air cooling, for instance when the temperature drops from 900 to 700 C. in the course of one and one-half hours, the alloy acquires a hardness of 88 Brlnell and a tensile strength of 7 2,000 pounds per square inch with 25% elongation in two inches.

Qopperalloys containing from 0.1% to 2% of beryllium and as high as 40% nickel are considered to be within the scope of the present invention. However, itis preiered that nickel should be present in the proportion of about 13 parts nickel to 1 part berylli by weight.

The electrical resistivity of the alloys coming within the present invention can be lowered by heat treatment. For example, the alloy of 951? copper, 4% nickel and 3% beryllium above-described has an electrical resistivity of 9.3 microhms per centimeter cube when quenched. By'subjecting the al= loy to a prolon ed heat treatment,i. e., heating at 7 00 for 1 hour and then gradually reducing the temperature over a period of 6 hours to 350 C.,the electrical resistivity of the alloy is brought down to 3. microhms. or about twice that oi metallic copper. A shorter heat treatment, 1 hour at 600 G,-brings the electrical resistivity to 5.2 microhms or about three times that oi copper. approximately the same electrical resistivity if air or furnace cooled from 900 G.

l claim:

1. An alloy containing about 0.1 to 2% of beryllium and up to about 10% nickel, with the balance principally copper.

lhe unquenched alloy will show.

2. An alloy containing about 0.3% beryl= part beryllium by weight, with the balance principally copper.

4. An alloy containing about .3 to 2% beryllium, from .1 to 40% nickel and the balance principally copper.

In testimony whereof, I afiix my signature.

MICHAEL G. OORSON.